for keystone

Signed-off-by: Kouhei Maeda <mkouhei@palmtb.net>
retrieve token, storage_url from response of keystone

Signed-off-by: Kouhei Maeda <mkouhei@palmtb.net>
fixes #2 support auth of keystone

Signed-off-by: Kouhei Maeda <mkouhei@palmtb.net>
increase version and update documents

Signed-off-by: Kouhei Maeda <mkouhei@palmtb.net>